Interlock mechanism



Sept 13, 1949., (i a, THiEME 2,481,629

INTERLOCK MECHANISM 7 Original Filed July 1., 1944 3 Sheets-$heet 1IJNVENTOR.

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INTERLOCK MECHANISM Original Filed July 1. 1944 3 Sheets-Sheet 2 j 27 [6px E a6 14 v. H34\ 1 w "A J. 44

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m 1 1 m Q m r M v Q My x h o m i m mi W 0 A 0 Q? E Patented Sept. 13,1949 INTERLOCK MECHANISM George B. Thieme, Jamaica, N. Y., assignor toBendix Aviation'Corporation, Norwood, Mass., a corporation of DelawareOriginal application July 1, 1944, Serial No.

Divided and this application March 11, 1946, Serial No. 653,673

4 Claims.

The present invention relates to interlock mechanisms, more particularlymechanisms for compelling a certain sequence of operations to be carriedout, as for instance in the opening and closing of valves in a chemicalreaction conduit system, especially operations in which a time factor isinvolved, to insure the carrying out of a process in predeterminedmanner, although it is not limited to such use.

This application is a division of my application No. 543,187, filed July1, 1944, and issued March 19, 1946 as Patent 2,396,759.

A novel interlock mechanism is provided which makes it possible to setup a predetermined sequence of locking and interlocking operationsrequiring the use of a set of keys, thereby eliminating the need forhuman supervision, inasmuch as the interlock mechanism of the inventioncompels or enforces insertion and removal of keys from the device inpredetermined sequence, and prevents key withdrawal until a certain timeinterval has elapsed. By varying the key holding and releasing action,and the length of time the key or keys will be held, interlockingmechanisms may be provided in accordance with the invention to affordcontrol of various types of operations.

It is accordingly a primary object of this invention to provide a novelinterlock mechanism which will constantly retain one of two keys againstremoval, and which, upon rotation of one of the keys through apredetermined angle, will lock both keys against removal until apredetermined time interval elapses.

Another object is to provide a signal device to indicate the durationand/or termination of said predetermined time interval.

A further object is to provide novel electrical operating and controlmeans for said signal device, as well as for the system as a whole.

The invention further aims to provide, in an interlock mechanism, novelswitch actuating and lock cylinder arresting mechanisms; a novel camassembly for controlling the operation of adjacent lock cylinders; anovel mount for the interlock assembly; and further novel interlockimprovemints and refinements to be hereinafter pointed ou Furtherobjects will become apparent as the specification proceeds inconjunction with the anneXed drawings, and from the appended claims.

In the drawings:

Figure 1 is a vertical sectional view through an interlock mechanismembodyingone form of this invention, taken substantially on the line I-Iof Figure 3;

Figure 2 is a vertical sectional view through the apparatus taken alonga vertical plane disposed at right angles to the plane of Figure 1;

Figure 3 is a horizontal sectional view taken along the line 3-3 ofFigure 2;

Figure 4 is a view showing the wiring diagram for the apparatus ofFigures 1 to 3 inclusive.

With continued reference to the drawings, wherein like referencecharacters have been employed to designate similar parts throughout theseveral views, I have illustrated the invention as being applied to aninstallation requiring incorporation of the switch parts in a gas andexplosion proof casing l0, equipped with end closure caps H and [2.However, it is to be understood that the invention is not limited to usewith a casing of this character. Case ID is provided with mounting lugsl3 for supporting it in any desired man ner.

The interlock mechanism of the invention is installed in the casing innovel manner, permitting maximum accessibility with a minimum ofmounting structure.

Supported on a flat upper surface of casing 10 is a housing l4 having aclosure I5 secured thereto in sealing relationship by means of capscrews [6 and a gasket [1. Secured to the upper face of closure l5, bymeans of cap screws H! or the like, are lock assemblies 19 and 2| havingkeys 22 and 23 respectively cooperating therewith in wellknown manner. Asheet metal thimble 24 is clamped under each lock barrel assembly and isprovided with a closure 25, the latter being anchored to the top ofclosure 15 by a retaining chain 26, and suitable swivel connections. a

The lock barrels shown are of well-known character and include shankportions projecting through openings in closure I5, and terminating inrockable shaft elements 21 and 28 respectively which are operativelyengaged with coupling members 29 and 3|. The latter transmit rockingmovements of the lock barrel shafts to the inter-: lock mechanismlocated within casing IS, in the manner now to be set forth.

Couplings 29 and 3! are engaged with rock shafts 32 and 33 respectivelyprojecting into casing l0, and from the foregoing it is apparent that ifit were not for the novel interlock mechanism of the invention, shafts32 and 33 could be rocked at will by inserting keys 22 and 23 in theirlooks and turning them.

While shafts 32 and 33 may be coupled to the interlock mechanism of theinvention in various ways, I preferably employ a novel assembly of partswhich functions to efficiently journal the shafts for rocking movement;to secure housing H to housing l; and also to operatively support theentire interlock mechanism in the housing as a unit. To this end shafts32 and 33 are journalled in flanged bushings 34 and 35, respectively,which as seen in Figure 1, are threaded into tapped openings in theupper wall of housing l3,

and function to secure casing l4 in tight engagement therewith. Collars36 and 31 secured to the upper ends of the shafts maintain them inproper vertically adjusted position. Tightly threaded on to the lowerends of bushings 34 and'35 are complemental bushings 38 and 39,respectively. The latter have reduced lower ends which project throughopenings in the upper plate 4| of a framework including a bottom plate42 and intermediate posts 43 secured thereto by cap screws 44. Plate 4|is rigidly secured to bushings 38 and 33 by means of nuts 45.

From the foregoing disclosure it is apparent that all that is necessaryto secure complete accessibility of the interlock mechanism is to removeclosure I and its associated lock barrels; remove collars 36 and 31: andunscrew bushings 34 and 35, which permits the entire interlock mechanismto be dropped down and removed from casing II] by way of one of theplugged openings.

Referring now to Figures 1 and 3, shafts 32 and 33 rigidly carry ratchetdiscs 41 and 48 at their lower ends, which respectively cooperate withpawls 49. The latter are pivoted on the under side of plate 4| and areurged into engagement with notches 50 in their ratchet discs by tensionsprings 5|. The pawl and ratchet assemblies accordingly effectivelyprevent counter-clockwise e rotation of the barrels, as viewed in Figure3. Rigidly secured to the underside of discs 4? and 48, by rivets or thelike are interlock discs 52 and 53 having notches 54 and 55 in theirperipheries. As seen in Figure 3, the periphery of disc 52 is receivedin notch 55 of disc 53, with the result that rocking movements of shaft33 in either direction is prevented. Y

Operation of the parts is further controlled by a solenoid 51 carried bya downwardly extending bracket 58 from plate 4| and having a plunger 59coacting with a single opening 8| (Fig. 3) in disc 52 carried by shaft32. The plunger is normally urged upwardly by a spring 62, so that whenthe solenoid is deenergized, plunger 53 will be projected by the springinto opening 6| upon rotation of shaft 32 through an angular distance of90 in a clockwise direction from the position of the parts illustratedin Figure 3.

Also coacting with plate 52 is a micro-switch 64 carried by a dependingbracket 65 carried by plate 4| and provided with an actuating arm 65,which is spring-urged upwardly and carries a roller 61 at its free end.The roller coacts with a cam 68 secured to the underside of disc 52. As

seen in Figure 3, cam 68 is provided with inclined.

end or ramp portions, and extends over an angular distance ofapproximately 90 around the disc. The micro-switch may be of anywellknown character and is operable to open a timer control circuit (tobe hereinafter described) when it is depressed, and to close the circuitwhen it is disposed in its upper position shown in Figure 2. The ratchetand interlock disc assemblies are secured to their respective shafts bynuts 1| and 12, and suitable keying means being employed to insureunitary rotation.

Taking up the operation of the structure so far described, it is to beunderstood that the parts are shown in the initia1 or starting positionin all the figures. Keys 22 and 23 cooperate with their lock barrelassemblies in such manner that they can be inserted and rotated through360 and then released, the keys and lock barrels embody coactingprojections which prevent removal in any other position, as is wellunderstood in the art.

In the position shown in Figure 3, key 23 has been rotated 180 from itsinsertion position and therefore is held against removal. Key 22 isdisposed in removal position and will be assumed to have just beeninserted in the apparatus. Pawl 49 prevents counter-clockwise rotationof the assembly with which key 22 is associated, and therefore the onlymovement possible is clockwise rotation. Upon clockwise rotation of key22 through approximately 90, plunger 59 is projected by spring 62 intoopening 5| of plate 52, thereby locking the key against furtherrotation. Coincidental with rotating key 22 through 90, cam 68 engagesroller 61 and depresses arm 65 of micro-switch 64 into circuit-breakingcondition.

Upon conclusion of the foregoing operation, the parts are locked againstfurther manipulation until solenoid 51 is energized, inasmuch as thenotch in disc 53 prevents rotation of key 23 in either direction andplunger 59 locks key 22 against rotation. Both keys are thereforeretained.

Any suitable form of timer mechanism may be incorporated with the deviceto introduce a defi-- by a motor 19, so that when micro-switch 54 is."

opened, coil 18 releases the clutch and couples motor 79 to the timermechanism, whereupon the timing cycle is initiated. The other side ofthe line 11 leads to a binding post 8|, to which a lead 82 from coil 18and motor 19 is connected.

Upon engagement of the jaw clutch in. the

manner just described, it causes a contact as sembly 83 to close, andthis action, through leads 84 and 85 and a binding post 86, closes themotor,

circuit. A contact assembly 8'! closes the circuit through an indicatorlight 88 while the timer is in operation, to give a visible indicationthat the timing operation of the apparatus is in progress.

At the end of the timing interval, contact assembly 81 engages itsopposite contact 85, extinguishing light 88 and energizing solenoid 51through lines 9| and 92. Upon retraction of solenoid plunger 59 in themanner just described, key 22 is released for further clockwise rotationbut is held against counter-clockwise rotation by pawl 49. Accordingly,upon rotation of key 22 through an additional 90 travel, from thestarting position) notch 54 of plate 52 is brought opposite plate 53,with the result that key 23 may now be rotated 180 clockwise andremovedand employed to carry out some other phase of operation in theparticular interlock-controlled system.

During the foregoing additional 90 rotation of key 22, cam 68 is sorotated as to allow roller 61 to roll off of its trailing end, restoringarm 55 to the circuit-making position shown in Figure 2, whereuponclutch coil 18 is re-energized, disengaging the clutch and stopping thetimer mo tor. This action also returns contact arm 67 to the midpositionshown in Figure l, thereby dc energizing the solenoid and resetting thetimer for the next cycle. When this occurs, spring 62 projects plunger59 into engagement with the underside of disc 52.

It should be observed that upon conclusion of the operation justdescribed, the parts are disposed 180 from the positions shown in Figure3, with the periphery of disc 53 received in notch 54 of disc 52, withthe result that the latter cannot be rotated in either direction.

Upon reinsertion of key 23 in look barrel 2|, and rotation thereofthrough 180", disc 53 is restored to the position shown in Figure 3.Since this places notch 55 adjacent disc 52, the latter may now berotated 180 clockwise, and key 22 removed. This final step restores theparts to the starting position, and after key 22 has been reinserted thecycle may be repeated.

It is accordingly apparent that the invention provides a pair ofrotatable key-receiving devices which are so interlocked that one key isfreely insertable and removable while the other is held against removal,and that means are provided whereby the inserted key, when rotated lessthan a full revolution, will be locked against further rotation until apredetermined time interval has elapsed, and that at the end of thatperiod it may be rotated a further distance sufiicient to permit removalof the other key, resulting in a mechanism which makes it possible toestablish a predetermined sequence of locking and interlockingoperations requiring the use of a set of keys, thereby eliminating theneed of human supervision in a system embodying key-controlled units.

The foregoing embodiment of the invention provides a single timed periodof key retention, and therefore is termed a single timer interlock. Theinvention also may be embodied in the form of a multiple timerinterlock, as further described and illustrated in my aforesaidapplication No. 543,187.

Inasmuch as it is impossible to rotate the parts during normal operationinto such position as to permit simultaneous removal or insertion ofboth of the keys, it is necessary, when initially assembling the device,to rotate the keys into their desired relative positions prior toinstalling cover I5 on casing l4. Durin assembly, shafts 32 and 33 arealso manually rotated into the desired predetermined angularrelationship. It is then a simple matter to apply couplings 29 and 3| toshafts 32 and 33, and then apply cover I5 to casing M.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced thereby.

What is claimed is:

1. In an interlock apparatus, a casing, a pair of flanged sleeveassemblies projecting through, and rigidly secured to one wall of saidcasing; a mounting plate disposed in said casing and having a pair ofopenings aligned with and fitting over the inner ends of said flangedsleeve assemblies; means for directly rigidly securing said plate tosaid sleeve assemblies, a shaft in each of said sleeve assemblies; meansdisposed externally of said casing for rotating said shafts; and meanscarried by said mounting plate for controlling rotation of said shafts.

2. The interlock apparatus defined in claim 1, wherein each of saidsleeve assemblies comprises an externally-threaded bushing screwed intoan opening in said casin and an internally-threaded bushing threadedover the inner end of said first bushing and having an externallythreaded portion of reduced diameter projecting through said mountingplate, and providing a shoulder bearing against said plate; and a nutthreaded on said last-named portion and pulling said shoulder intoclamping engagement with said mounting plate.

3. In an interlock apparatus, a main casing; an auxiliary casing seatingagainst said main casing; a pair of sleeve assemblies projecting throughthe neighboring walls of said casing and securing the latter together; amounting plate disposed in said main casin and rigidly secured to saidsleeve assemblies; a shaft rotatable in each of said sleeve assembliesand projecting into said auxiliary casing; a cover secured to saidauxiliary casing and carrying means for actuating said shafts; and meanscarried by said mounting plate for controlling actuation of said shafts.

4. The interlock apparatus defined in claim 3, wherein each of saidsleeve assemblies comprises a bushing threaded into a wall of said maincasing and having a flange engaging a wall of said auxiliary casing andmaintaining the latter in clamping engagement with said main casing.

GEORGE B. THIEME.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 537,311 Schade Apr. 9, 18951,134,625 Locke Apr. 6, 1915 1,676,971 Weaver July 10, 1928 2,126,333Kirk Aug. 9, 1938 2,409,762 Jones Oct. 22, 1946 2,437,785 Mucher Mar. 6,1948

